37 Sensors Kit
I don't remember where I bought this kit. It's branded "Robotlinking" but robotlinking.com is gone, now it's https://sunfounder.com/
Closet light sensor
Today I am looking at making a closet light. I had an IKEA light in there but it quit. It uses a reflective sensor and an LED strip.
I think I can put one of the reflective sensors from the 37 sensor kit. They have "Avoidance" and "Tracking" sensors. I can just hook one of them up to a spare M5StickC and there you go. It will send MQTT updates to Home Assistant and HA will tell the light to go on via a Martin Jerry switch. "Simple". Ha.
I can use either the HAT connector or the Grove connector.
Tracking module
3 pin connector: signal, power, ground Mine has 4 pins, this one has only 3. (One pin is NC)
It has an LM393 comparator. Sensitivity can be adjusted with a trimpot. It has 2 visible LEDs to give status. D1 show power (labeled "PLED"). D2 shows state ("SLED").
Tracking module
This is a newer version of the Avoidance sensor.